This invention relates generally to the coding and duplication of keys. More particularly, this invention relates to machines for copying a pattern of dimples onto a key blank with or without a pattern key.
Locking systems employing keys which are bitted with patterns of dimples commonly function to provide a high level of security. The dimple configurations facilitate multiple levels of master keying. Exemplary dimple patterns are configured in rows of dimples disposed at preselected locations from a reference position on the key with each dimple having a preselected incremental depth. In order that the key may be operative regardless of which side is inserted in the keyway of a cooperating lock as the "up" side, opposing side surfaces of the key blade may have identical patterns comprising a right row and left row of dimples. The narrow key edges between the opposing surfaces may also include a row of dimples. The rows of dimples of the side surfaces may be oriented at a constant acute angle to the surface to facilitate key control.
Duplication of such aforedescribed keys on conventional key machines has been problematical due to difficulties in accurately locating the positions of the dimples, difficulties in cutting the correct incremental depths of the dimples and also difficulties in correctly duplicating the acute angular orientation of the dimples. The problems in duplicating the dimple patterns are increased when duplicates are made from second generation and later generation duplicate keys or from old keys or from keys or duplicate keys which have been inaccurately made on conventional key machines. Accordingly, the present invention is directed to a new and improved key machine which is particularly adapted for keys configured with dimple patterns as hereinbefore described.